Difference of adherence, proliferation and osteogenesis

Abstract

【Abstract】Objective: To study the adherence, proliferation and osteogenesis of mesenchymal stem cells (MSCs) cultured on different HA/ZrO 2 composites. Methods: The simplex and graded HA/ZrO 2 compo-sites were prepared using dry-laid method. The surface to-pography of the composites was observed by scanning electron microscope (SEM). The MSCs were isolated from rabbits and cultured on experimental groups (simplex HA/ ZrO 2 composite, graded HA/ZrO 2 composite, pure HA or pure ZrO 2 coatings respectively) and control group (ordinary culture plate). Then, we observed the adherence, prolifera-tion and osteogenesis of the MSCs, detected the cellular alkaline phosphatase (ALP) activities, extracted total RNA and detected the mRNA expression of collagen I, osteocalcin and osteopontin using the reverse transcription and poly-merase chain reaction (RT-PCR) method. Results: The SEM images confirmed that the surface of the simplex HA/ZrO 2 composite was coverd by discon-tiguous HA layer with clear visualization of the partial ZrO 2 matrix, while the surface of the graded HA/ZrO 2 composite was fairly rough with porosity. X-ray diffraction showed that after high temperature sintering, the ZrO 2 phase still remained, while the HA phase was transformed to β-Ca 3 (PO 4 ) 2 , α-Ca 3 (PO 4 ) 2 and CaZrO 3 phases on the surface of both composites. Cell culture indicated that the HA/ ZrO 2 composites supported cell attachment. Neither ALP expression nor mRNA expression of collagen I, osteocalcin or osteopontin from RT-PCR results showed significant de-viation among four groups. Conclusion: Among these four composites, the graded HA/ZrO 2 composite promotes the MSCs proliferation and the osteogenic differentiation to a certain extent. Key words: Zirconium oxide; Durapatite; Mesenchy-mal stem cells